A comparison of methods for assessing preference for social interactions

Researchers have evaluated a variety of methods for assessing preference for social interactions, and generally have found that such assessments accurately identify differentially reinforcing, preferred interactions. However, few researchers have compared methods for assessing preference for social interactions, and none have done so with participants across different skill levels. The current study compared the stability and validity of hierarchies produced by social interaction preference assessments (SIPA) and picture-based multiple stimulus without replacement preference assessments (MSWO) with 8 individuals diagnosed with autism spectrum disorder (ASD). The MSWO most often produced valid hierarchies for participants who could match, identify, and tact pictures of social interactions and that the SIPA most often produced valid hierarchies for participants who could not identify or tact pictures of social interactions. A vocal paired-stimulus preference assessment (PSPA) was also conducted with a subset of participants who communicated vocally, and it produced valid hierarchies. Considerations and recommendations for selecting a method of assessing preference for social interactions are discussed.     

Evaluating preference for and reinforcing efficacy of fruits and vegetables compared with salty and sweet foods

Children diagnosed with autism spectrum disorder are often more selective in their food preferences than their typically developing peers. Additionally, many preferred food selections have minimal nutritional value. We evaluated the preference for, and reinforcing efficacy of, fruits and vegetables compared with salty and sweet foods, which are often used as edible reinforcers. Multiple-stimulus preference assessments were conducted to identify preferred foods, and reinforcer assessments were conducted to determine the reinforcing efficacy of more preferred foods. Fruits and vegetables were sometimes preferred over salty or sweet foods and often functioned as reinforcers. Future research should incorporate fruits and vegetables into preference assessments when identifying putative reinforcers.     

Murray Sidman: A life of giving

Murray Sidman's contributions to the science of behavior span many areas including avoidance behavior, coercion and its effects, stimulus control, errorless learning, programmed learning, stimulus equivalence, and single-subject methodology. He was also a great mentor to many and helped shape the discipline we now call behavior analysis. In this memoriam, we briefly highlight his scholarly legacy and share some personal anecdotes.     

Visual target control of schedule-induced aggression in white king pigeons (columba livia)

Visual target control of schedule-induced attack was studied in domesticated pigeons by exposing them to successive and simultaneous target preference procedures involving a fixed-time food schedule and projected target images. Pigeons preferred attacking an image of a conspecific head over a headless bird regardless of the height of the latter. Images of an intact bird and of a head alone were equally effective in controlling attack and more effective than the headless bird. Neither the eye nor four. other head-related features exclusively controlled attack. The combined results suggest that the head of an intact conspecific target selectively controls schedule-induced attack and that the effectiveness of the head in directing attack is inversely related to its physical integrity as a unit without regard to specific features. These results are consistent with reports that the head and head-related features of an intruder control reproductive aggression in birds.     

A comparison of teaching tacts with and without background stimuli on acquisition and generality

We evaluated whether teaching tacts of images with or without backgrounds would affect acquisition during teaching and generality across untaught targets with four children diagnosed with autism spectrum disorder. Including backgrounds could slow acquisition but bolster generality across other media containing backgrounds, whereas removing backgrounds may improve acquisition but result in poorer generality. Overall, acquisition rates were similar across conditions for three children, although one child displayed consistently slower acquisition during the background condition. We rarely observed generality to untaught targets when programming extinction, but embedding differential reinforcement or teaching additional images with backgrounds led to equally successful outcomes irrespective of initial teaching conditions. Teaching with or without backgrounds may result in marginal differences in acquisition of teaching and untaught targets, especially when arranging supplemental procedures during tests for generality. We discuss the importance of intrasubject replication, considerations when testing for generality, and implications for practice.     

The role of instruction preference in analogy learning: Brain activity and motor performance

This study examined the role of verbal instruction preference when learning motor skills by analogy. During skill learning, analogies are a useful tool for providing knowledge about how to move. It has been argued that analogy instructions reduce reliance on verbal information processes during motor planning, compared to traditional forms of instruction (i.e., explicit rules about how to move). This may be reflected by reduced verbal activity in the brain, measured by EEG alpha power at the temporal region, as well as reduced verbal-motor cross-communication (EEG T7-Fz coherence) during the preparation phase of a movement. Preference for using verbal or visual instructions is likely to influence the efficacy of analogy instructions. This study investigated whether preference for verbal instructions was related to a) changes in performance and b) changes in verbal-cognitive information processing during performance of an adapted basketball task after instruction by analogy. Basketball novices with a high preference for verbal instructions (n = 15) showed significantly decreased activation of verbal brain regions when they used the analogy (high-alpha power), but their performance remained stable. Novices with a low preference for verbal instructions (n = 13) did not show a significant decrease in activation of verbal regions, and their performance deteriorated significantly after introduction of the analogy instruction. It is likely that both cognitive and performance changes after analogy instruction depend on personal aspects of information processing, such as verbal preference.     

Contextual control of equivalence-based transformation of functions

The transformation of functions refers to the untrained acquisition of stimulus functions among members of stimulus equivalence classes or relational frames. Although it is widely assumed that contextual control over the transformation of fuctions must exist, this has not yet been conclusively demonstrated in laboratory studies. Four experiments are reported in which (a) stimulus equivalence classes were established, (b) a conditional stimulus function was trained for one member of each of the classes, and (c) multiple-exemplar procedures were used to train and test for contextual control over the transformation of the stimulus function within the classes and to assess whether it generalized to new equivalence classes. Although a significant amount of training was required, the procedures ultimately resulted in the contextual control of function transformation for 9 of 10 participants and generalized contextual control for 4 of 5 participants.     

A new approach to the formation of equivalence classes in pigeons

Four pigeons were given simultaneous discrimination training with visual patterns arbitrarily divided into two sets, with the stimuli in one set designated A1, B1, C1, and D1 and those in the other set designated A2, B2, C2, and D2. In sequentially introduced training phases, the pigeons were exposed to a series of reversals to establish AB and then CD equivalences. In subsequent testing sessions, a subset of stimuli from one set served as positive stimuli and those from the other set as negative stimuli on training trials, and transfer of the reinforced relation to other members of the sets was tested with nonreinforced probe trials. The pigeons were trained further on AC and BD equivalences and then were tested for the emergence of untrained AD and BC equivalences. Two of the 4 pigeons exhibited the emergence of one of these untrained equivalences, evidence for the emergence of transitive relations. This finding suggests that the pigeons established three-member functional equivalence classes by incorporating separately trained multiple equivalence relations. Repeated reversal training and probe testing enabled us to explore the formation and expansion of functional equivalence classes in pigeons.     

Stimulus control topographies and tests of symmetry in pigeons

Pigeons were tested for symmetry after A-B training under conditions designed to avoid problems that may prevent its emergence, namely the change of stimulus location in testing relative to training and the lack of requisite discrimination training. In Experiment 1, samples appeared in two locations during baseline training to minimize the impact of stimulus location. Experiments 2 and 3 included multiple-location training along with additional identity and symbolic matching training, respectively, to explicitly train all of the simultaneous and successive stimulus discriminations required for testing. Experiment 4 provided reinforcement for symmetrical matching relations with some stimulus sets (with multiple-location training) prior to symmetry testing with different sets. In all experiments, pigeons showed no evidence of symmetry despite the fact that baseline (A-B) matching transferred to novel locations. Additional tests for reflexivity (Experiment 2) yielded similar outcomes. These results indicate that the change in stimulus location is not the sole reason that pigeons do not show symmetry and increase the plausibility of arguments that symmetry and other indexes of stimulus equivalence may be beyond the capabilities of the pigeon.     

Naming and categorization in young children: vocal tact training

In three experiments, 2- to 4-year-old children, following pretraining with everyday objects, were presented with arbitrary stimuli of differing shapes. In Experiment 1A, 9 subjects were trained one common tact response, "zag," to three of these and a second tact, "vek," to another three. In category match-to-sample Test 1, 4 subjects sorted accurately when required only to look at the sample before selecting from five comparisons. The remaining 5 subjects succeeded in Test 2, in which they were required to tact the sample before selecting comparisons. Experiment 1B showed, for 2 of these subjects, that tact training with 12 arbitrary stimuli established two six-member classes that were still intact 6 weeks later. In Experiment 2, 3 new subjects participated in a common tact training procedure that ensured that none of the exemplars from the same class were presented together prior to the test for three-member classes. Two subjects passed category Test 1 and the third passed Test 2. Tests showed subjects' listener behavior in response to hearing /zog/ and /vek/ to be in place. These experiments indicate that common naming is effective in establishing arbitrary stimulus classes and that category match-to-sample testing provides a robust measure of categorization.